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<TITLE>[Chapter 10] 10.4 Custom Events</TITLE>
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<h2 CLASS=sect1><A CLASS="TITLE" NAME="JNUT2-CH-10-SECT-4">10.4 Custom Events</A></h2>

<P CLASS=para>
Beans can use the standard AWT event
types defined in the <tt CLASS=literal>java.awt.event</tt> package, but
they do not have to.  Our
<tt CLASS=literal>YesNoDialog</tt> class defines its own event type,
<tt CLASS=literal>AnswerEvent</tt>.  Defining a new event class is really quite
simple; <tt CLASS=literal>AnswerEvent</tt> is shown in
<A HREF="ch10_04.htm#JNUT2-CH-10-EX-3">Example 10.3</A>.

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<h4 CLASS=example><A CLASS="TITLE" NAME="JNUT2-CH-10-EX-3">Example 10.3: The AnswerEvent Class</A></h4>

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<PRE>
package oreilly.beans.yesno;
public class AnswerEvent extends java.util.EventObject {
  protected int id;
  public static final int YES = 0, NO = 1, CANCEL = 2;
  public AnswerEvent(Object source, int id) {
    super(source);
    this.id = id;
  }
  public int getID() { return id; }
}
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<P CLASS=para>
Along with the <tt CLASS=literal>AnswerEvent</tt> class,
<tt CLASS=literal>YesNoDialog</tt> also defines a new type of event
listener interface, <tt CLASS=literal>ActionListener</tt>, that
defines the methods that must be implemented by any object
that wants to receive notification from a
<tt CLASS=literal>YesNoDialog</tt>.  The definition of <tt CLASS=literal>AnswerListener</tt> is
shown in <A HREF="ch10_04.htm#JNUT2-CH-10-EX-4">Example 10.4</A>.

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<h4 CLASS=example><A CLASS="TITLE" NAME="JNUT2-CH-10-EX-4">Example 10.4: The AnswerListener Interface</A></h4>

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<PRE>
package oreilly.beans.yesno;
public interface AnswerListener extends java.util.EventListener {
  public void yes(AnswerEvent e);
  public void no(AnswerEvent e);
  public void cancel(AnswerEvent e);
}
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